Steam-boiler.



H. L. DOHERTY.

STEAM BOILER.

APPLICATION FILED JAILZO. 1911.

Patented July 30, 1912.

4 SHEETSSHEET 1.

Mme was Henry L. Doherty, vwewfoz 35!, his GHQ mun H. L. DOHERTY,

STEAM BOILER.

APPLICATION FILED JAN. 20, 1911.

1,034;,2 1 8. Patented July 30, 1912.

4 SHEETSSHEET 2.

Win Leases: I Henr LDuherty, avwew roz m I lahis GttOLHGiJ H. L. DOHERTY.

STEAM BOILER.

APPLICATION FILED JAILZO, 1911.

Patented July 30, 1912.

4 SHEETS--SHEET 4.

witnesses: Henry L. Doherty. awuewfoz HENRY L. Bonnier, or ew Your, 1:. Y.

STEAM-BOILER.

Specification of- Letters Intent. P t ted Ju1y30,1912

ss licanoimeu auar 20, 191-1. Serialxlini 602,111.

To all'whom it may-concern;

Be it known that I, HENRY L. DOHER'I'Y,

a citizen. of the United States, and a resident of New York city, in the county of New York and State of New York, have invented certain new and useful Improve.-

ments in Steam-Boilers, of" which the following is a specification.

This invention relates to steam boilers and, in particular, to a steam boiler fired with-producer gas firom a self-containedgas producer.

The object of my invention is the furnish ing of a steam boiler of such construction, and having a method of operation. such, that a very rapid rate of circulation of the water is secured, thus efiecting the maximum rate ofheat conductance from the gaseous products of the combustion of the water, and the maximum possible utilization of the heat of the fuel secured.

Briefly, my invention consists of a steam boiler comprising in combination, a gas producer having a movable grate, a combustion chamber, a steam generating chamber di vided by vertical partitions into three-"compartments, a plurality of steam drums and cooperating mud drums, a plurality of tubes connecting each air of cooperating drums, a water heater 0 novel construction and a recuperator for heating the air used in the combustion of the fuel, as well as various other features which will be fully set forth later. .'The arrangement is such that the gas formed in the gas producer of the apparatus is burned 1n the open combustion chamber in such a way as to secure complete combustion with the minimum supply of air, the extremely hot products of this combustion pass through the middle compartment of the steam generating chamber in cofitact with the middle group of water tubes, thence divide and return through the two side compartments of the steam generating chamber, after which one stream passes to the water heater and the other stream to the air recuperator. By subjecting the water in the middle group of water tubes to' the action of the extremely hot combustion gases, the tubes, themselves, be-

ing of comparatively small cross-section, I convert the bulk ot the water in the tubes to steam. The tubes of the'middle group are thus filled with a foamy mass oi steam recuperator.

and water. The generation of steam in the two side grou of tubes is much slower, owing to. the fact that the combustion gases have been greatly reduced in temperature by the time they have reached the side compartments The fluid filling oi the tubes of theside groups is therefore much heavier than the column of fluid in the tubes of the middle group. -There is, therefore, a considerable hydrostatic pressure exerted by the fluid in the side tubes, through the connecting mud upon the fluid in the middle tubes. The result is that the velocity of flow of the through y the middle tubes is very-high, and the rate ofheat transmission high in consequence.

In the accompanying drawings, I have shown the preferred 'ilormof my invention, in ,which the-same numerals are used to de-.'

note the corresponding parts in all the fig- Figure 1 is a vertical longitudinal section oi the apparatus along the line A A of Fig. 2 and B B oi Fig. 5 Fi 2 is a, verticaltransverse section along is e line C (l of Fig. 1. Fig. 3. shows the feed-water heater invertical; section and 4 shows the Fig. 5 is a horizontal crosssection of the steam generating chamber along the lines D D of Fig. 1 and: G Gof Fig. 2 showing clearly the chamber filled with the water tubes and the vertical partitions which cause the gases to flow in the direction of the arrows. Fig. 6 is a diagrammatic plan view of t e apparatus. Fig. 7' is apart vertical section of the lower portionof the combustion chamber along theline Ark of Fig. 2 but looking in the opposite direction from which Fig. 1 was taken, showing the connection :torv the producer gas, from the producer to the combustion chamber. Fig. 8 is a part horizontal sectionof the combustion chamber along the E E. oi Fig. andF F of 7 showing the relative positions of the tangential inlets for the combustion gas and secondary air. 7

' A clear understanding of? my invention and 6 are suitable covers for the clinker and coal compartments of the hopper 3.

As the sprocket-wheel 7 is made to slowly rotate in the direction of the arrow, by' any suitable driving gear, it causesv the upper part of the chain grate 8, to assume a motion toward the opposite end of the producer, from that where the fuel is'fed, the

. rate of sugh motion depending upon the gasification. J p I ducer l0pis led to the combustion chamber 12 through the flue 11, as shown in Fig. 7. As

rateof gasifi'cation of the fuel, 1, on the grate, 8, and being so regulated that bv the time the fuel fed in at the front erid of the producer has been-practically completelythe gas enters the lower part of the combustion chamber 12, it is mixed with air entering through the fine 13 on the opposite side of the chamber. The height of the combustion chamber is such as to allow several convolutions of the gaseous stream, thus obtaining a thorough mixture and complete Y combustion before leaving the combustion chamber through the flue 14 The combustion chamber is of circular cross-section and preferablyhaving an arched roof, 15. 5 The air and as are entered tangentially'at opposite si es, thus forming a helical flame. By'this device I have found that I can secure a' very complete and rapid combustion of the producer gas with the minimum supply of air, thus insuring a very high flame temperature. This method of combustion and form of combustion chamber I, do notherein claim, as it is claimed in my application Ser. No. 358414, filed Feb.'.8th, 1907.

I The steamgenerating chamber 16 is inclosed by the sidewalls 21 and 21' andthe end walls 22 and 22 and is divided into three heating compartments, 23, 24 and 24, by the vertical partitions or baflle walls'25 5 and 25 which extend the entire height of the chamber, but they do not traverse the entire length of the chamber but leave spaces 26 and 26 so as to connect the middle compartment 23 with the lateral compartments 24 and 24.

A plurality of steam drums, 17, 17 and- 17", are set transversely of the steam generating chamber. A corresponding number of mud drums occupy the lower part of the said chamber, each beingset directly under its cooperating steam drum. A large number of tubes, the ones occupying the middle compartment 23, at least, being preferably.

of comparatively small cross-section, join each steam drum with its cooperating mud drum.

The hot combustion gases pass from the combustion chamber. 12, throughthe flue 14, and enter the middle compartment 23 of steam generating chamber 16. This. central' compartment, 23, is of such cross-section ber is at the rear of the chamber, as is shown in the=drawings, the current of combustion gases Wlll move toward-the front of the chamber in the central compartment'and will d1vide 1 to two currents at thefront' end of the chamber, one current following the direction of the arrow through the passage 26 and assuming a direction toward the rear end of the chamber in the compartment 24'. In the rear wall 22 is the flue 27, through which flue and pipe 28 the combustion gases, after heating the water tubes in the compartment 24, are led to a recuperato'r, 29. The other current will follow the direction of the arrow through the passage 26 and will also assume a direction toward the rear of the chamber in the compartment 24, heating the tubes in this compartment and leaving the compartment through the flue 30. The

pipe 31 leads this second current of com: bustion gases to a water heater, 32, where a further portion of its sensible heat is used to heat the feed watersupplied to the boiler.

, As stated before, the current of combustion gases leaving the compartment 24' of the steam generating chamber 16, is led to the recuperator 29 by the conduit 28. A valve, 28, on the conduit 28 regulates the flow of gas through the recuperator 29. The recuperator 29 m'ay be of any suitable type,

. the one shown comprising a plurality of parallel, serpentine, combustion gas flues cn-- veloping a corresponding number of air flues. The main current of 'COIIlbllSiilOIl gases is divided, as it enters the top of the recuperator, between the several combustion gas flues, the several currents again uniting in the transverse flue 37. 33 is the casing of the recuperator. The recuperator is divided into several parallel vertical compartments byvthe partitions 34, which partitions extend theentire height and length of the recuperator except at the points of distribution and collection, thereby forming a distributing and a collecting flue respectively. The horizontal partitions 35 extend alternately from the front and back of the recuperator to a short distance from the opposite end and are oined to the vertical partitions, thus forming the continuous scrconduit 38 to the large underground flue 39] which leadsall waste gases to the chimney.

pent ine flues 36. 37 is the distributing gas-' the cross-flue 37 and is distributed to the plurality of serpentine fines-36, one of which is shown in "Fig. 4. Flowing downward through the fiues 36'the gases unitein the collecting flue 37 and are led from the recuperator, after giving up the larger-part of their sensible heat to the an flowlng 1n the opposite direction therethrough, by the.

4:0 is a blower fo-rcingair through the pipe 42 to the distributing air pipe 43 placed in the collecting gasflue 37'. The air .is thus i v producer.

divided into the same number of parallel currents as the combustion gas. The air pipes, 44, are placed substantially in the centers of the gas flues 36.

In the distributing gas flue 37 is placed the collecting air pipe 43',to which collect-J 'ing pipe is attached the oil-take air pipe 45 which leads the heated air from the re cuperator. .56 are hangers for supporting the air pipes 44in the recuperator29, and

57 is the lagging covering said recuperator."

The current of heated air flowing through the main pipe 45 is divided into three cur-.

rents, one current flowing through the pipe 46 to the injector 47 furnishes the primary air for supporting the combustion in the gas The secondary air supplied for the combustion of the producer gas in the combustion chamber '12, is led to that chamher by the pipe 48 (in the drawingsshown, this is anextension of the pipe 45) and thence through the flue 13. -A small part of the main current is taken oil by the pipe49 and ledunderthe stationary grate i), for the purpose of burning whatever carbon may have escaped combustion in the producer 10. Valves, 467, 48 and L9, on the respective pipes 46, 48-and 4 9, serve to regulate the currents-of air flowing through them.

The primary air .vflowing through the injector'47 and injector throat 50 induces a current of hot combustion gases from the steam generating chamber 16 through the this current of combustion gas is re the air onthe nozzle by means of the valve .47. I As the primary air enters the space 54 below the movable grate. 8, it is distributed along the length of the grate in proportion to the amount ofcombustihle fuel along the grate. That is to say, a greater'amount; 01'- .air is caused to pass through the front end 'of-the grate, where the fuel bed is thicker, than through the rear end of the grate,

where the fuel bed is thinnendue to thecontraction of the mass on the grate' as the space 58"the'gases are led awa carbon is burned out. This distribution is accomplished by placing a partition or baille plate, 55, between the upper and lower .parts of the movable grate 8 and in a direction inclining. downward toward the front of the grate. The plate extends clear across the chamber, extending into the two side walls. The up r rear end is so constructed as to substantially prevent any air from passingthrough-the grate at that end. The

effect of thisbalile is to continuously di minish the passage open to the air under the grate 8, ,from the front .to the rear end of the grate. The distanceof the baflie below the grate should be so regulated that the resistance-which it ofiers to'the flbw of the air along the grate shall be sufficient to cause the major portion of the air to pass through the mass on the front of the grate, and continually diminishing portions through the successive sections of the is an important feature of my invention, as it is evident that for economical working the air must be distributed along the length of the fuel bed in proportionto the quantity 'ofcombustible thereon." This roper distribution of the air through the elfbed is regulated by the inclination and length of the baflle plate 55, as described above. The gas formed in the producer '10 by the combustion of the fuel and the air, leaves the producer by the large flue IL and entersthe comb us' tion chamber 12 tangentially, as already stated. The second current of combustion gases, after passing through the com rantment 24 and flue 30, enters thecondult '31, leading to the water heater'32. The water -.heater may also be of any preferred type,

but I prefer to-u'se one of the form shown in grate from the front to the rear end thereof. This ,Fign. 3.v This is of a novel" construction,

so arranged that there is no circulation of the water passing therethrough. -I have not claimed this specific invention herein,

but reserve the rlght to claim 'it' in-a laterapplication The hot gases'enter at'tlie' top I of the water heater through a pipe, 31, into an open distributing gas space, Y 58. This heater, the upper ends of the inclosing walls and the upper header 59. This header, as"

space is formed by the top of the water well as a'slmilar lower header, 59', contains numerous openings for the insertion of the vertical gas tubes 60 which connect the distributing space 58 with the collecting'space 58. The hot gases are distributed among the several rows of tubes 60 (onl one row of which is shown in Fig. 3) and ow downward through the tubes 60, giving up their sensible heat to the feed water, which flows in the opposite direction through the'intertubular space; of the water heater, as explained later. After passing through 'the from the water-heater through the conduit 61 to the underground flue 39 and thence to the chimney. 32 is a means of access to the gas space 58 for .cleaning purposes. The water heater is, preferably insulated with some suitable lagging, 62.

The water to be fed to the boiler isforced through the pipe 64 by the pump 63 and enters the lower part of the .intertubular space of the water heater just above the ,lower col lecting gas space 58', It completely fills the space 65 between the tubes 60, entirely surrounding them and flows upward through the heater, its temperature rislng, due to the absorption of the heat given up by the opposite flowing hot combustion gases through the tube60. By, this device of causing the -heating gases to travel downward through.

the heater while the water is caused to travel upward, it is apparent that the greatest heatingefiect is at the surfaceof the water in the heater and diminishes toward the bottom of the heater. There is thus, very little tendency to set up convection currents, the

- I water moving slowly from the bottom to the top of the water heater as a mass, with very little local'circulation. By this arrangement the lower ends of the tubes 60 are surrgund' ed with water whichis at substantially the temperature of the water entering throu h 64:. The cond1t1ons are therefore very a-- vorable for the recuperation of the heat of the combustion gases flowing through the.

water heater, and-these leave the heater at. a

comparatively low temperature. Theheated water leaves the water heater by the pipe 66, which is placed just below the distribwater to the water heater may be controlledby the respective valves 31 and 64' uting gas space 58. The flow of gas and I placed respectively on the pipes 31 and 64. The heated water is now led to the several water spaces of the steam drums .17, 17 and 17, and this may be done in any convenient vmanner. In the accompanying drawings is shown a pipe, 67, connected with the feed water pipe 66. The Water leaving pipe 66 divides Into two. currents, one flowing through 67 to the pipe 68 and the other through 67 to the pipe 68. This arrange ment of the feed water pipes is shown clearly in Fig.' 6. The pipes 68 and 68' traverse, respectively, opposite ends of all creasing the rapid circulation at which I aim. The upper drums communicate with each other through the'curved pipes 71, 71.

and 72, 72, which are also placed over the -lateral compartments 24' and 24, respecthe drums.

The steam liberated from the water in the drums 17,17 and 17" is led out through their respective connections 73, 73 and 73 into the main steam pipe 74, which carries the steam from all the drums to where it is to be used, and also serves for equalizing the pressure int-he several drums. The lower, or mud drums, may be made much smaller than the steam drums, and-each contains a device for collecting the sediment precipitated from the impure feed water. I have shown perforated pipes, 75, 75 and 75", placed longitudinally in each mud drum for this purpose. The sediment collects at the lowest point of the boiler and is forced through the perforations 76 which are placed along the sides of the pipes and near their lower surfaces and is blown out by the blow-,oif pipes 77, 77" and 77", by opening the valves 78, 78 and 7 8", respectively, and carried away;by the waste pipe 79. 80 is the watergage and 81 the steam gage. The steam gage is connected to the steam space of one of the steam drums by the pi e 82.

The drums, tubes and containe water are supported in any suitable manner, but I prefer the support to be independent of the brickwork, and I have shown each of 83", from suitable guides. Bolts, 84, 84 and 84", pass through the upper ends respectively of the straps 83, 83' and 83", and

stood that the above described system of beamsis one way of supportin the drums, tubes and contained Water-,but do not limit -myself to that particular method of support. The lower mud drums are supported from the uppe r drums, by the water tubes. This may be done in this case, as the large number of tubes connecting each pair of drums make the strain brought on any individual tube negligible.

Openings, 89;.give access to the interior of the steam generating chamber 16. The

brick settin'g isfor the purpose ofinclosing the chamber and does not support any part of the boiler proper. n

90 and 91 are doors to the openin s 90' and 91-, respectively, through whic the the steam drums, 17, 17 and 17", suspend ed by their respective straps, 83, 83 and lot Ill

ash and clinker discharged from the grate 8 are Withdrawn.

It is apparent that, by regulating the distribution of air, for combustion of the fuel on the movablegrate, along the length of that grate in pro ortion to the quantity of carbon on the di erent sections of the grate, I will obtain a gas of normal quality. This air distribution may be" regulated,;\as alreadyexplained, by some suitable meansplaced below the fuel bed, such as the inclined baffle 55, or a .horizont-al plate pro vi-ded with vertical baflles at intervals and extending across the producer and below the lower part of the grate with suitably graduated openings. i

It is desirable .to have a ine'ans of protecting the grate and this I accomplish by feed:

ifililg1 clinker, as explained before, below the e I y In the ordinaryianethods of operating power plants there is-always a-considerable A proportion of-the fuel used lost, duefto the falling through the grate of portionsotunburned carbon. Inv the present apparatus practically allof the carbon of the fuel is burned in the producer. This is insured by allowing the ashes, which may contain av certain amount ofunburned carbon, to fall -upon a secondary grate, and allowing a small amount of air to pass through this secondary grate and burn whatevercombus- 'tible material may have escaped combustion in the producer proper; In this way the proportion of the carbon of the fuel whichis wasted is reduced to a minimum. -In the drawings is shown a combustion.

chamber connected with the producer where the gas led from the producer is burned with the neceswry amount ofair. This combustioi chamberis circular in cross-section and has a spherical top or dome and'is lined entirely with fire-brick. As already explained, the gas and air enter the bottom .of this chamber tangentially at acomparatively high'veloeity. There is therefore produced a helical flame havingseveral complete :con volutions in contactwith each other.

One of the important features of this invention is themethod used to secure 'a rapid circulation of both the heatin gases and the water in thelt ubes, so that t e evaporation in the tubes and drums will be;a maximum.

It is theaim in all'types of.v boilers to obtain'a rapid circulationof the water through the tubes and drums and thus obtain a rapid generation of steam since, as is well known, the rate of heattransmission varies about as the sq; .root of the velocity of the circulation. As explained before, the hot combustion gases enterithersteam generating chamber in the center of one of its ends and pass through this chamber by a middle compartment which contains the middle group of water tubes. The cross-section of this middle compartment, depending upon the dis tance between the division walls 25 and 25", is such as to cause the .hot gases flowing through it to have relative velocity. The high velocity of the'hot. gasesin contact with the water tubes in the compartment causes a rapid rate heat transmission from thegasesto the water in the tubes. This is due to the fact that the rate of heat transmission from fluids to metal depends upon thevelocity of flow of the gases in contactwith the metal, as already explained. The time of contact of the gases and tubes is of course shortened, but the heat transmitted by the higher velocity of the gases more; than balances-the lower amount of heat transmitted through the tubes by the shorter interval of contact of gases with the f-tubes. 1 After passing throu h the length of the the central group of tubes. We have therefore, that the gases heating the end tubes in the lateral or side compartments are traveling at a lower velocity'and are at a lower temperature than the gases heating the central tubes contained in the central compartment. There is consequently a rapidheating and-rising of the water in the central groups of all the banks, of tubes and a corresponding rapid downward motion of the water in the two end groups of each bank of tubes, to take the place of the water rising in the central oups. There is thus a rapid circulation groups. of tubes tothe centers of the mud drums and up the central groups again.

The circulation in each pair of cooperating steam and mud drums is independent of the circulation in the other pairs of drums, the

connections between'the steam drums serving to equalize the water level in them.

The feed water is entered in the coolest parts of the drums above the tubes in which the circulation is downward, and so immediately passes vertically, through these'tubes,

liberating itself "of most of its impurities while passing \throughth'ese tubesand the 'mud'drums The sediment naturally falls to thebottom ofthe mud.drums,'from where r it is readily blown off when necessary:

The waste gases leaving. the boiler at A rom the center of each steam drum to the ends thereof and down the end about 500.to 600 F. are not allowed toescape directly to the atmosphere through a chimney, but their sensible heat isutilized bon dioxid of this portion of the combustion gases is mostly broken down by reaction with the carbon of-the fuel to carbon monoxid. As this reactioncauses the absorption of; a large amount of heat from the useful work.

fuel bed, it enables the temperature thereof to be keptat a point below the clinkering temperature of the ash, whereby the grate kept. free from obstructive masses and the fuel bed in a condition easily permeable by the draft current.

Withthese methods of recuperation, above described, together with the preliminary drying and, continual slow feeding of the coal, which does away with the necessity of opening doors and allowing an inrush of cold airwhen intermittent firing is resorted to, I obtain the recovery of the maximum amount of heat units of the fuel in I' have not herein claimed specifically the form of gas-producer and traveling grate shown, but reserve the right to claim these specifically in another application.

Having described my invention, what I claim is: I

1. In a steam boiler, a chamber divided into forward-flow and return-flow passages.

for the heating gases, an upper steam-drum "and a lower mud drum each of said drums being set so as to traverse all of said passages and to lie cross-wise .to the direction of flow of the heating gases through said passages and a plurality of water-tubes connecting said drumsi a 2. In a steam boiler, a chamber divided into forward-flow and return-flow passages for the heating gases, saidflpassages being so arranged that the flow of gases therethrough is substantially horizontal, a plurality of steam-drums set transversely of all of said passages in the upper part thereof, and a plurality of mud-drumsset transversely of saidpassages in the lower part thereof, and

a plurality of water-tubes connecting said drums. v

' 3. In a'steam boiler, a chamber divided into forward-Hoyt and return-flow passages for the heating gases, a plurality of steamdrums set transversely of all of said passages in the upper part thereof, and a lurahty of mud-drums set transversely 0 all of said passages in the lower part thereof, each of said mud-drums being set substan tially vertically under one of said steamdrums and cooperating with said steamdrum, and a plurality of water-tubes connecting-each of said steam-drums with its cooperating mud-drums.

4. Ina steam boiler, a chamber divided into forward-flow and return-flow passages for the heating gases by substantially vertical partitions, a plurality of steam-drums set transversely of said passages in the upper part thereof, and a 'plurality of muddrums set transversely of said passages in the lower part thereof, each of said muddrums cooperating with one of said steamdrums, and a plurality of water tubes connecting each of said steam-drums with its cooperating mud-drum.

5. In a steam boiler, a chamber divided into forward-flow and return-fiowpassages for the heating gases, a plurality of steam drums set transversely of all of said passages in the upperpart thereof, and a plurality of mud-drums set transversely of all of said passages in the lower part thereof, each of said mud-drums cooperating with one of said steam-drums, a plurality of Water-tubes connecting each of" said steamdrums with its cooperating mud-drum, and a plurality of tubes cross-connecting said steam-drums.

6. In a steam boiler, a chamber divided into forward-flow and return-flow passages for the heating gases by substantially vertical partitions, passages around one end of said partitions establishing communication between said forward fiow and said return flow passages, a plurality of steam-drums "set transversely of said passages in the upper part thereof, and a plurality of-muddrums set transversely of said passages in the lower part thereof, each of said mud drums cooperating with one of said steam drums, a plurality of water-tubes connecting each of said steam-drums with its cooperalting mud-drum, and a plurality of tubes connecting the water spaces of said steam-drums.

7. In a steam-boiler,- in combination, a chamber divided into forward-flow and return-flow passages for the heating gases by substantially vertical partitions, passages around one endof said partitions establishing communication between said forward flow and said return fiowpassages, a plurality of steam-drums set transversely of said passages in the upper part thereof, and a plurality of mud-drums set transversely of said passages in the lower part thereof, each of said mud-drums cooperating with one of said steam-drums, a plurality of'tubes connecting each of said steam-drums with its cooperating mud-drum and a plurality of steam tubes establishing communication between the steam spaces of the said steamdrums.

8. In a steam-boiler, in combination, a chamber divided into a plurality of passages for the heating gases by substantially vertical partitions, said partitions extending substantially from the bottom to the top of said chamber, a plurality of steam drums in the upper part of said passages, a plurality of mud-drums in the-lower part of said passages, each of said mud-drums cooperating with one of said steam-drums, a plurality of tubes connecting the vapor space of-each of said steam-drums with the adjacent drum or drums, and a plurality of tubes connecting the water space of said steam drums with the water space of the adjacent steamdrum or drums. i

9. In a steam-boiler, in combination, a chamber divided into a plurality of passages foriheheating gases by means of a plurality of substantially vertical partitions, passages around one end of said partitions establishing communication between said passages for heating gases, a substantially; horizontal steam-drum set in the upper part of said passages, a substantially horizontal muddrum set in the power part of said passages,

and a plurality of water-tubes connectingsaid steam-drum with said mud-drum.

10. In a steam-boiler, incombination, a chamber divided into. a middle and two side passages for the heating gases by means of two substantially vertical partitions, said partitions extending substantially from the bottom to the top of said chamber, a sub stantially horizontal steam-drum settrans versely of said passages in the upper part thereof, a substantially horizontal muddrum set transversely of said passages in the lower part thereof, and a plurality of water-tubes connecting said steam-drum with said mud-drum.

11. In a steam-boiler, in combination, a chamber divided into a middle and two side passages for the heating gases by means of two substantially vertical partitions, a plurality of substantially horizontal steamdrums, each of said steam drums being set transversely of all of said passages in the upper part thereof, a-plura-lity of substantially horizontal mud-drums set transversely of said passages in the lower part thereof, and a plurality of water-tubes connecting the said steam-drums with the said muddrums.

12. In a steam-boiler, in combination, a heating chamber, 'a plurality of substantially vertical partitions, said partitions extending substantially from the bottom to the top of said heating chamber and divldmg said chamber into a middle and two side passages for the heating gases, a plurality of steam-drums set transversely of said pasand cooperating therewith, and a plurality sages in the-upper part thereof, a plurality of mud-drums set transversely of'said pas sages in the lower part thereof, each of said mud-drums being located substantially vertically underneath one of said steam-drums of water-tubes. connecting each steam-drum with its cooperating mud-drum. w

13. In a steam-boiler, in combination, a heating chamber, a plurality of substantially vertical partitions extending substantially from the bottom to the top of said chamber, said partitions dividing said heating cham-. her into amiddle and two side passages for the heating gases, a plurality of steam drums set transversely of said passages in the upper part thereof, passages connecting the steam-space of each of said steam-drums with a common steam passage, whereby thesteam-spaces of the said steam-drums are placed in communication with each other, a plurality of tubes connecting the water space of each drum with the water spaces bf the adjacent steam-drums, a plurality of mud-drums set transversely of the said passages for heating gases in'the lower part thereof, each of said mud-drums being set substantially parallel with and vertically underneath one of said steam-drums, and a plurality of water tubes connecting each of 95 said steam-drums with the underlying muddrums, whereby each of said steam-drums is made to cooperate with its said underlying mud-drum.

14. In a steam-boiler, in combination, a heating chamber, said heating chamber being divided into a plurality of longitudinal passages for the heating gases by means of substantially vertical partitions, a plurality of substantially vertical partitions, passages around the ends of said partitions farthest from the place of entrance of the heating gases, said passages establishing communication between said longitudinal passages, a plurality of steam-drums located in the up- 0 per part of said longitudinal passages, a mud-drum or a plurality of mud-drums located in the lower part of said passages and a plurality of water-tubes connecting the said mud-drum or drums with the said steam-drums.

15. In a steam-boiler, in combination, a steam-generating chamber. comprising a middle passage for the flow of the high temperature combustion gases entering the chamber, in one direction, two smaller passages, one located on each side ofsaid middle passage, for the return flow of the partially spent combustion gases, two substantiallv vertical partitions extending substantially from the bottom to the top of said gas generating chamber. said partitions forming the said middle and side passages, a pluraL ity of steam-drums set transversely of said combustion gas passages in the upper part 13 thereof, one or more mud-drums set transversely of said combustion gas passages in the lower part thereof, and aplurality of water tubes connecting said mud-drum or drums with the said plurality of steamdrums. I

16. In a steam-boiler, in combination, a steam-generating chamber having two substantially vertical longitudinal partitions therein, whereby the said generating chamber is divided into a middle longitudinal passage for the flow of the high-temperature combustion -gases enteringrthe chamber in: one direction, and a smaller longitudinal passage on each side of said middle passage for the return flow of the partially spent combustion, gases, a plurality of steamdrums, each of said steam drums being'set transversely of all of said combustion passages in the upper part thereof and a plurality of mud-drums set substantially parallel to ,said steam-drums, one of said mud-drums being located, substantially, vertically underneath each of saidisteam-drums and cooperating therewith, and a plurality of water tubes connecting each steam-drum with its cooperating mud-drum, whereby a circulation of water is established between the lower mud-drums and their cooperating steam-drums, the said water ascending through the water-tubes occupying the said middle passage for combustion gases and descending through the tubes occupying the said side passages for combustion gases. 17. In a steam-boiler, in combination, a

"steam-generating chamber having two substantially vertical longitudinal partitions therein of a less length than the length of said chamber, whereby the said generating chamber is divided into. a middle longitudinal' passage for the flow of the high-temperature combustion gases entering the said chamber in one direction, and a smaller longitudinal passage on each side of said middle passage for the return-flow of the partially-spent combustion gases, the said side passages being in free communication with the said middle passage at the extremity of said steam-generating chamber farthest from the place of entry of said combustion gases, a plurality of steam-drums set transversely of said combustion gas passages in the upper part thereof and a plurality of mud-drums set substantially parallel to said steam-drums, one of said mud-drums being located substantially vertically beneath each of said steam-drums and cooperating therewith, a plurality of water-tubes connecting each-.steam-drum with its cooperating muddrum, a plurality of tubes cross-connecting the water spaces of said steam-drums, said cross-connections being located in the said side passages for combustion gas, and a pipe connecting the steam-space of each of said steam-drums with acommon steam conduit. I

said chamber, two substantially vertical lon-a gitudinal partitions in said chamber, said partitions abutting against the front wall of said chamber but stopping short of the rear Wall of said chamber, whereby the said steam-generating chamber is divided into a. middle longitudinal passage and two side longitudinal passages, the said side passages being in communicationwith said middle passage around the rear ends of said partitions, a passage in the front'wall of said chamber communicating with the said middle passage of said chamber for conducting the hot combustion gases to said middle passage and one or more passages in the front Wall of said chamber in communication with each of said side passages for the exit of the spent combustion gases from said side passages, steam-drums in the upper part of said passages and one or more mud-drums in the lower part of said passages, a plurality of water-tubes in each of said passages connecting the said niudgitudinal partitions in said chamber, said partitions abutting against the front wall of said chamber but stopping short of the rear wall of said chamber, whereby the said steam-generating chamber is divided into a middle longitudinal passage and two side longitudinal passages, the said side passages being in communication with said middle passage around the rear' ends of said parti tions, a passage in the front wall of said chamber communicating with the said middle passage of said chamber'for conducting the hot combustion gases to said middle pas sage and one or more passages in the front wall of said ch amber in communication with each of said side passages, for the exit of the spent combustion gases from said side passages, a plurality of steam-drums set transversely to said passages in the upper partthereof, a plurality of tubes cross-connecting the water spaces of the adjacent steam-drums, the said cross-connections being located in the said side passages, a valved water feed-pipe communicating with the interiors of said steam-drums near the ends thereof, a pipe connecting each of said steam-drums with a common steam conduit, whereby the steam spaces of the several steam-drums are in communication with .slO

each other, means for indicating the water level in said steam-drums, a plurality of -mud-drums set parallel to said steam-drums, one of said mud-drums'being located vertically beneath each of said steam-drums, a

plurality of water tubes in each of said longitudinal passages connecting the said steamdrums with the said mud-drums, wherein in the operation of said boiler, a rapid circulation of thecontained water is established between the said mud-drums and the said steam-drums, the water ascending in the bank of tubes occupying the said middle passage and descending through the banks of tubes occupying the said side passages.

2-0. The combination of a gas producer, a combustion chamber, a passage connecting said combustion chamber with said gas producer, a steam-generating chamber and a passage connecting said combustion chamber with said steam-generating chamber, the said steam-generating chamber comprising forward-flow and return-flow passages for the heating gases, aplurality of steam-drums set transversely of said passages in the upper part thereof, and a plurality of muddrums set transversely of said passages in the lower part thereof, each of said muddrums being set substantially vertically un der one of said steam-drums and cooperating with said steam-drum, and a plurality of water-tubes connecting each of said steamdrums with its cooperating mud-drum.

21. In combination, a gas producer, a combustion chamber, a passa e connecting said gas producer with sai combustion chamber, a steam-generating chamber, a passage connecting said combustion chamber with said steam-generating chamber,- the said steam-generating chamber comprising, forward-flow and return-flow passages for the combustion gases from said combustion chamber, a plurality of steam-drums set transversely of said passages in the upper part thereof, and a plurality of muddrums set transversely of said passages in the lower part thereof, each of said muddrums cooperating with one of said steam:

drums, a plurality of tubes connecting each of said steam-drums with its cooperating mud-drum and a plurality ofsteam tubes establishing communication between the steam spaces of the steam-drums.

22. In combination, a gas producer, a combustion chamber, a passage connecting said gas producer with said combustion chamber, a steam-generating chamber and a passage connecting said combustion chamber with said steam-generating chamber, the

said steam-generating chamber comprising in combination a middle and two side passages for heating gases, said passages being formed by two substantially vertical partitions and the two Walls of said chamber parallel to said partitions, a substant ally her with the said steam-generating chamber, the said steam-generating chamber comprising in combination a middle and 30 two side passages for heating gases, a plurality of steam-drums set transversely of said passages in the upper part thereof, a plurality of mud-drums set transversely of said passages in the lower part thereof, each of said mud-drums being located substantially vertically under one of said steamdrums and cooperating therewith, and a plurality of water-tubes connecting each steam-drum with its cooperating mud-drum.

24. In combination a gas producer, a combustion chamber, a passage connecting said gas producer with said, combustion chamber, a steamgenerating chamber, and a passage connecting the said combustion chamber with the said steam-generating chamber, .the said steam-generating chamber comprising a middle passage for the flow of the high temperature combustion gases entering the steam-generating chamber in one direction, two smaller passages one located on each side of said middle passage for the return-flow of the partially spent combustion gases, aplurality of steamdrums set transversely of said combustion gas passages in the upper part thereof, a plurality of mud-drums set transversely of said passages in the lower part thereof, one of said mud-drums being located substantially vertically beneath each of said steamdrums and cooperating therewith, and a plurality of water-tubes connecting. each steam-drum with its cooperating mud-drum, whereby-a circulation of water is established between the lower mud-drums and their co- 115 operating steam-drums, the said water ascending through the water-tubes occupying the said middle passage for combustion gases and descending through the tubes 00'- cupying the said side passages for combus- ,120 tion gases.

25. In combination, a gas producer, a: combustion chamber, a passage connecting said gas producer with said combustion chamber, a steam-generating chamber, and .125 a passage connecting the said combustion chamber with said steam-generating chamher, the said steam-generating chamber comprising, inclosing outer walls, t w o substantially vertical, longitudinal partitions there- 130 in, of aless length than the length of said chamber, whereby the said generating chamber isdivided into a middle longitudinal passage for the flow of the high temperature combustion gases entering the said chamber in one direction and a smaller longitudinal passage on each side of said middle passage for the flow of the partially spent combustion gases in the reverse direction, the said side passages being in free communication with the said middle passage at the extremity of said steam-generating chamber farthest from the place of entry of said combustion gases, a plurality of steam-drums suspended transversely of said combustion gas passages in the upper part thereof, a plurality of mud-drums in the lower partzof said combustion gas passages, one of said mud-drums being located substantially vertically underneath each of said steam-drums, a plurality of water-tubes con-,

necting each steam-drum with its cooperating mud-drum, whereby the said muddrums are placed in communication with their. cotiperating steam-drums and suspended from said steam-drums, a plurality of tubes cross-connecting the water spaces of said steam-drums, said cross-connections being located'in the side passages for combustion gas, and a pipe connecting the steam space of each of said steam-drums with a common steam conduit.

26. In combination, a gas producer, a combustion chamber, a passage connecting said gas producer with said combustion chamber, a steam-generating chamber, a passage opening from the upper part of said combustion chamber connecting said chamber with the steam-generating chamber, a passage connecting the said combustion chamber with 1 the air discharge-flue of an air recuperator; the sand steam-generatmg chamber COIi'1})l'lS- ing inclosing outer walls, two substantially vertical, longitudinal partitions in said chamber, said partitions abutting against the front wall of said chamber but stopping short of the rear wall of said chamber, whereby the said steam-generating chamber is divided into a middle-longitudinal passage and two side longitudinal passages, the said side passages being in communication with said middle passage around the rear ends of said partitions. a passage-in the front wall of said chamber, communicating with the said middle passage of said chamber, for conducting the hot combustion gases to said middle passage, and one or more passages in the front wall of said chamber in communication with each of said side passages for the exit of the spent combustion gases from said side passages. steam-drums a plurality of connecting WfltQlEhlllGS. said .water-tubes occupying both the middle and sldepassages of said steam-gencrat1ng chambustion chamber, a passage connecting said gas producer with said combustion chamber, a steam-generating chamber, a passage opening from the upper part of said combustion chamber connecting said chamber with the said steam-generating chamber, .a passage connecting the lower part of the said combustion chamber with the air dischargeflue of an air recuperator; the said steamgenerating chamber comprising inclosing outer walls, two substantially vertical longitudina-l partitions in said chamber, said partitions abutting against the front wall of said chamber but stopping short of the rear wall of said chamber, whereby the said steam-generating chamber 'is divjded into a middle longitudinal passage and two side longitudinal passages, the said side passages being in communication with said middle passage around the rear ends of said partitions, a passage in the front wall of said chamber communicating with the said middle passage of said chamber for conducting the hot combustion gases to said middle passage and one or more passages in the front Wall of said chamber in communication with each of said side passages for the exit of the spent combustion gases from said side passages, a plurality of steam-drums suspended transversely of said passages in the upperpart thereof, a plurality of tubes cross-connectingthe water spaces of the adjacent steam-drums, the said cross-connections being located in the said side passages, a valved water feed-pipe communicating with the interiors of said steam-drums near the ends thereof, a pipe connecting each of said steam-drums with a common steam conduit, whereby the steam spaces of the several steam-drums are in communication with each other, means for indicating the water level in said steam-drums, a plurality of mud-drums in the lower part of the combustion gas passages of said steam-generatsaid boiler a rapid circulation of the contained water is established between the said mud-drums and the said steam-drums, the water ascending in the bank of tubes occupying the said middle passage and descending in the banks of tubes occupying the said side passages. a

28. In combination, a water-heater, an air heater, a gas producer, a combustion chamber, passages connecting the lower part of said combustion chamber with said gas producer and said air heater, respectively, a steam-generating chamber, a passage conmeeting the upper part of said combustion chamber with said steam=generating chamber, the said steam generating hamber comprising, a middle longitudinal passage for receiving the high-temperature combustion gases from said combustion chamber, and two side passages, one on each side of said middle passage for receiving the partially spent combustion gases from said middle passage, a plurality of steam-drums set transversely of said combustion gas passages in the upper part thereof, a plurality of mud-drums in the lower part of said combustion gas passages,a lurality of watertubes connecting each 0 said steam-drums with its corresponding mud-drum, whereby there is an upward circulation of water established from the said mud-drums to their cooperating steam-drums through the water-tubes occupying the said middle passage for combustion gases and a downward J. M. MOMILLIN, F. L. BLAoKnURN, 

